Generally, multilayer glass panels comprise two glass panes and a spacer interposed between the two glass panes to provide an air layer therebetween. Since the multilayer glass panels thus constructed have an excellent thermal insulation capability, they serve as an energy saver when used in combination with housing and building sashes.
Glazing gaskets for use on most typical multilayer glass panels that have heretofore been available are of a continuous channel-shaped extruded structure which comprises a rubber layer adapted to project from a sash groove and a resin layer adapted to be inserted in the sash groove, the rubber layer and the resin layer being joined to each other. A continuous glazing gasket is cut into lengths that match the vertical and horizontal dimensions of a multilayer glass panel. The glazing gasket lengths are then fitted over the vertical and horizontal edges of the multilayer glass panel, and the vertical and horizontal edges of the multilayer glass panel which are covered with the glazing gasket lengths are inserted into the corresponding grooves of a sash. In this manner, the multilayer glass panel is installed in the sash.
The above process of mounting the glazing gasket on the multilayer glass panel is tedious and time-consuming and is of low productivity because the glazing gasket is manually fitted over the edges of the multilayer glass panel.
For increased productivity, there has recently been proposed a method of molding a glazing gasket onto a multilayer glass panel by extruding a molding material directly onto the peripheral edges of the multilayer glass panel with molding dies which are connected to an extruding machine and shot pumps, as disclosed in WO2006/046349.
The proposed method will be described below with reference to FIG. 12 of the accompanying drawings.
First, a multilayer glass panel 1, with its plane oriented vertically, is placed on and held by a worktable 2. Then, a pair of molding dies 3a, 3b is pressed against the respective face and back surfaces of a peripheral edge of the multilayer glass panel 1.
The molding dies 3a, 3b are connected to a molding material shot pump, not shown, and an adhesive shot pump, not shown. A predetermined amount of melted molding material is supplied from an extruding machine, not shown, to the molding material shot pump, and temporarily stored in the molding material shot pump. At the same time, a predetermined amount of a melted hot-melt adhesive is supplied from an adhesive supply pump, not shown, to the adhesive shot pump, and temporarily stored in the adhesive supply pump. Thereafter, the adhesive supply pump supplies the melted hot-melt adhesive under pressure to the molding dies 3a, 3b, which discharge the melted hot-melt adhesive onto the face and back surfaces of the peripheral edge of the multilayer glass panel 1, thereby coating the face and back surfaces of the peripheral edge of the multilayer glass panel 1 with respective layers 4 of the melted hot-melt adhesive. At the same time, the molding material shot pump supplies the melted molding material under pressure to the molding dies 3a, 3b, which discharge the melted molding material 5 onto the layers 4 of the melted hot-melt adhesive, forming respective layers 5 of the melted molding material thereon.
One or both of the molding dies 3a, 3b and the multilayer glass panel 1 are moved relatively to each other by a feed mechanism, not shown, so that the molding dies 3a, 3b are continuously displaced along the peripheral edge of the multilayer glass panel 1. The layers 4 of the melted hot-melt adhesive and the layers 5 of the melted molding material are thus continuously applied to the face and back surfaces of the peripheral edge of the multilayer glass panel 1, forming glazing gaskets 6 thereon.